This invention relates generally to the addition of chemicals to fused baths, and more particularly to the addition of aqueous solutions of materials to essentially non-aqueous fused baths. Application Ser. No. 759,763, filed Jan. 17, 1977, entitled, "Liquid Additions to Fused Chemicals Baths", now U.S. Pat. No. 4,113,511 and commonly assigned herewith, discloses a system for addition of aqueous solutions of chemicals to essentially non-aqueous fused chemical baths. (These baths are normally referred to as "salt" baths in the trade although they may contain chemicals which are not defined as salts in classical chemical definitions, e.g. hydroxides, permanganates, etc.) Typical examples of such baths are described in U.S. Pat. Nos. 3,790,489; 3,260,619; as well as many other patents.
Said Application Ser. No. 759,763 describes how aqueous solutions of the chemicals are sprayed through nozzles under a hood onto fused high temperature baths. The water is vaporized into steam under a hood, and the steam is exhausted through a duct while the remaining chemicals fall onto the fused bath. Agitation of the bath mixes the essentially non-aqueous chemicals into the bath. The duct in this prior application communicates with the main hood. Such aqueous solution liquid addition has been found to be an excellent way to add materials to a fused bath, giving good control of added material, and allowing great flexibility in the addition of material to fused baths.
However, it has been found that with this type of aqueous solution liquid addition there may, and often does, occur appreciable amounts of splattering of the fused salt in the region where the material is being added. Some of the splattering material strikes this hood and solidifies thereon. As the additions continue, the material builds up on the interior of the hood. This build up often collects around the opening between the duct and the hood tending to clog this opening and preventing the discharge of the steam from the hood. This forces the steam out around the hood. Since the hood is partially submerged in the bath, this actually causes the steam to enter the bath to get out from the hood, causing much splattering and an unsafe condition.